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Rohloff Lever Shifters

Started by Tosspot · · Last activity · 8 posts · 552 views

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Cycling Equipment
Published
18 October 2006
Last activity
20 October 2006
Original author
Tosspot
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8
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  1. Much as a twist grip lends itself to a Rohloff hub, I'd like to try some
    sort of under bar lever system.

    Ideally something like the rapid fire system, but since the indexer is
    in the hub this is obviously not on, however, there must be a way using
    friction shifters.

    Anyone got any ideas?

  2. Tosspot said:

    Much as a twist grip lends itself to a Rohloff hub, I'd like to try some
    sort of under bar lever system.

    Ideally something like the rapid fire system, but since the indexer is
    in the hub this is obviously not on, however, there must be a way using
    friction shifters.

    Anyone got any ideas?


    Well, I'd never say it was impossible, but given the amount of cable the shifter has to take up to get all 14 gears, you would need a lever with a long throw. Also, since there is no low or high normal, you still need both cables, so the lever would need to be rigged "in line" so to speak. If you rigged it with two levers, you would need to have some kind of crossover mechanism to keep both cables tight.
    I can't help but think if there was a way to do it, Mr Rohloff would have done it.
    I've never really put much thought into alternatives because I like the rotary shifter just fine.
    Dan

  3. "Tosspot" <[email hidden]> wrote in message
    news:[email hidden]...

    Quoted message said:

    Much as a twist grip lends itself to a Rohloff hub, I'd like to try some
    sort of under bar lever system.

    Ideally something like the rapid fire system, but since the indexer is in
    the hub this is obviously not on, however, there must be a way using
    friction shifters.

    Anyone got any ideas?

    In a derailleur system, the shift cable pulls the shifter parallelogram
    one direction. When the cable is slackened a spring in the
    derailleur pulls the parallelogram back the other way.

    Rohloff shift cables work entirely differently. There are two cables.
    One cable pulls one direction and the other pulls the other direction.
    Think of a cable wrapped around a pulley - you pull on one end of
    the cable and simultaneously let out the other end of the cable
    to move the pulley one direction and reverse the process to move
    the pulley the other direction.

    Shifters for derailleurs only need to pull or slacken one cable.
    A Rohloff shifter must simultaneously pull on one cable while
    letting out slack in the other cable. You won't be able to do this
    with any shifter designed for a derailleur. You will have to use
    the one supplied by Rohloff or design and machine one entirely
    on your own.

    BobT

  4. BobT wrote:
    <snip>

    Quoted message said:

    Shifters for derailleurs only need to pull or slacken one cable.
    A Rohloff shifter must simultaneously pull on one cable while
    letting out slack in the other cable. You won't be able to do this
    with any shifter designed for a derailleur.


    <snip>

    Not quite correct. The *original* Shimano Positron system used a dual
    cable system, similar in concept to the Rohloff shifter, to activate an
    indexed rear derailleur. These were made in the mid-'70's and were rare
    back then, so finding them now will be next to impossible. I did find a
    twist-grip shifter for this system on Ebay:
    http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280034179753
    but that's not what the OP is looking for.

    Jeff

  5. JeffWills said:

    BobT wrote:
    <snip>

    Quoted message said:

    Shifters for derailleurs only need to pull or slacken one cable.
    A Rohloff shifter must simultaneously pull on one cable while
    letting out slack in the other cable. You won't be able to do this
    with any shifter designed for a derailleur.


    <snip>

    Not quite correct. The *original* Shimano Positron system used a dual
    cable system, similar in concept to the Rohloff shifter, to activate an
    indexed rear derailleur. These were made in the mid-'70's and were rare
    back then, so finding them now will be next to impossible. I did find a
    twist-grip shifter for this system on Ebay:
    http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280034179753
    but that's not what the OP is looking for.

    Jeff

    Are you saying these work for Rohloffs? Was there a lever version?

  6. Nate Knutson said:
    JeffWills said:

    BobT wrote:
    <snip>

    Quoted message said:

    Shifters for derailleurs only need to pull or slacken one cable.
    A Rohloff shifter must simultaneously pull on one cable while
    letting out slack in the other cable. You won't be able to do this
    with any shifter designed for a derailleur.

    <snip>

    Not quite correct. The *original* Shimano Positron system used a dual
    cable system, similar in concept to the Rohloff shifter, to activate an
    indexed rear derailleur. These were made in the mid-'70's and were rare
    back then, so finding them now will be next to impossible. I did find a
    twist-grip shifter for this system on Ebay:
    http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280034179753
    but that's not what the OP is looking for.

    Jeff

    Are you saying these work for Rohloffs? Was there a lever version?

    Just to recapitualte I'm familiar with the Rohloof, I have two, I've
    fitted them myself. What I'm trying to get rid of is the twist shifter
    and replace it with something else, ideally something that ressembles a
    conventional setup.

    On the twist grip front, something I've not tried is motorcycle throttle
    assemblies which use a positive push/pull arrangement. I actually have
    a spare one so I might try it out of interest.

  7. Somewhere I've seen photos of the twist shifter knob mounted
    on a sawed-off bar end. With a setup like that, there might be a way
    of jury-rigging a handle onto the knob, and voilá - a (somewhat
    oversized) thumby.

    You got to be very careful if you don't know where you're going, because you might not get there.

    - Yogi Berra

  8. Snortley said:

    Somewhere I've seen photos of the twist shifter knob mounted
    on a sawed-off bar end. With a setup like that, there might be a way
    of jury-rigging a handle onto the knob, and voilá - a (somewhat
    oversized) thumby.

    That's on an Atlantis owned by the unstoppable Mr. Brown:
    http://harriscyclery.com/atlantis/atlantis640-01.jpg
    as seen on
    http://www.sheldonbrown.com/harris/rohloff.html

    Jeff

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